Pulp-engine.



N0. 62%970. Patented Allg. |899.

F. L. STEVENS.

PULP ENGINE. (Applicatin med Fen 9, 189e.)

2 Sheets-Sheet l (No Mudei.)

No. 629,970. Patented Ang. l, |899.

r. L. STEVENS. y

PULP ENGINE.

[Application med. Feb. 9, 1898.) (No Mode.) I 2 yShams-*Sheet 2.

lgy.

Z a Ci? MM- @n UNITED STATES- PATENT 'OFFICE'.

FRANK L. s'rEvENs, or Hoosion FALLS, NEW YORK.

PULP-ENGINE.

SPECIFICATION forming part of Letters Patent No. 629,970, dated August 1, 1899.

Application led February -9. 1,838. `Serial No. 669,618. (No model.)v

To all! whom, t may concern:

Be it known that I, FRANK L. STEVENS, a citizen of the United States, residing at Hoosick Falls, county of Rensselaer, and State` of New York,have invented certain newaud useful Improvements in Pulp-Engines, of which the following is a speciiication.

The invention relates to such improve-- ments; and it consists of the novel construction and combination of parts hereinafter described and subsequently claimed.

Reference may be had'to the accompanying drawings and the letters of reference marked thereon, which form a part of this specification.

Similar letters refer to similar parts in the several figures.

Figure l of the drawings is a top plan view of my improved pulp-mixing engine. Fig. 2

zo is a side elevation of the same.V Fig. 3 is a vertical cross-section of the same, taken on the broken line 3 3 in Fig. l, viewed in the direction of the arrow. Fig. 4 is a vertical longitudinal section taken on the broken line' 2 5 4 4 in Fig. 1. Fig. 5 is a similar section taken on the broken line 5 5 in Fig. 1.

` The object of my invention is to produce a more uniform stock in paper-pulp engines and facilitate mixing.

My invention consists of mechanism for successively stratifying the divisive currents of pulp-stock each time they pass the grinding mechanism in a pulp-grinding engine.

I have shown in the drawings a double engine, in which A is the vat, divided by the parallel mid-fellows A and A2 into the two roll-channels As and A4 and the intermediate return-channel A5. The beater-rolls A6 and A7 are fixed upon the common shaft A8, provided with suitable bearings A9 in the usual well-known manner. The rolls are rotated by the belt-pulley A1O in `the direction indicated by the arrows, causing the stock to iiow between the respective rolls and bed-l plates A12 up over the backfalls A13.y As

' heretofore constructed the currents -coming from each roll enter the return-channel in an accidentally-mixed condition and leave such channel in equal quantities, being divided by 5o the divisive wedge or plate A,

My improved mechanism forstratifying the divisive currents is located between the backs of the rolls and the inletv of the return-channel, and consists of the elevated bed C, leading from the backfall in one ofthe roll-channels around over the lower bed C', which leads from the backfall in the other roll-channel.

The two beds, with their side walls, form continuations, respectively, of the roll-channels and are maintained wholly separate from each other until they discharge into the returnchannel which is common to both, thus forming the two orifices C2and C3 of approximately the same shape; being each of the same width as the return-channel and disposed one directly over the other, so that the currents coming from the two beater-rolls are evenly distributed or stratified in layers the one over the other as they enter the return-channel. Thestrata are evenly divided vertically, as before explained, when they leave the common return-channel, soA that one-half of each stratum goes to one roll and the other half of each stratum to the other roll, Where the strata-sections are thoroughly mixed with each other and the stock reground by the respective rolls, just one-half of the stock which in the previous passage of the rolls was ground by one roll now being ground by the other roll.

In prior constructions if one of the rolls became defective through wear, improper adbe uniformly` ground, because there would be some which would never reachk the perfect roll, and a long and uncertain time would be required to produce even a second quality of stock.

By stratifying the divisive currents and directing approximately equal parts of each to the respective rolls or grinding mechanisms I not only secure the greatest uniformity, but can with facility evenly mix colors with the stock to produce colored pulp for paper.

I have shown my stratifying apparatus applied to a double engine which produces two separate or divisive currents; but it is equally applicable to any engine capable of producing divisive currents.

What I claim as new', and desire to secure by Letters Patent, is-

1. In a pulp-engine, the combination with beating and current-producing mechanism; of lmeans for successively dividing and strati- IOO fying the moving stock, and guiding the stock in stratified form to the beating mechanism, substantially 4as described.

2. In a pulp-engine, the combination with beating and current-producing mechanism; of means for dividing vertica1ly,and stratifying horizontally, the moving stock, Whereby the divisive currents respectively colnprise the strata; means for vertically dividing the strata and guiding the divisive strata to the beating and current-producing mechanism, substantially as described.

3. In a pulp-beating engine, the combination with a vat having a roll-channel and a return-channel provided with means fordelivering to the return-channel divisive currents; of stratifying-channels through which the divisive currents enter the return-channel on parallel planes, one above the other, substantially as described.

4. In a pulp-engine, the combination with y a vat having a pair of roll-channels and an intermediate return-channel; of a pair of beater-rolls and backfalls in the respective roll-channels and a pair of stratifying-channels located one above the other between the two backialls and thev return-channel and discharging into the return-channel, subL stantially as described.

5. The herein-described method of treating paper-pulp which consists in beating the stock, stratifying the beaten stock by separating it into two horizontal layers, dividing the stratified layers vertically, and separately beating and mixing the divisive layers.

In testimony whereof I have hereunto set my hand this 15th day of January, 1898.

FRANK L. STEVENS. VVitnesses GEO. A. MosHER, FRANK C. CURTIS. 

